The overall objective is to create and sustain an independent research program on the brain mechanisms of selective auditory attention in humans. This will be accomplished through a combination of basic research involving patient-volunteers and mentored instruction. The candidate will draw on his previous post-doctoral experience in human auditory physiology, but direct his effort towards higher-order cognitive functioning of the auditory system taking advantage of the unique opportunity afforded by invasive electrophysiological research in neurosurgical patient-volunteers. The on-campus training environment for the candidate includes several leaders in auditory physiology and psychology. The candidate has further secured an off-campus co-mentor with specific and abundant experience in selective auditory attention in humans. The institutional commitment has allowed the candidate to concentrate his clinical responsibilities in a very narrow field of neurosurgery allowing full access to potential research subjects, but restricting non-research responsibilities to a minimum (25%). The research objective is to generate new information concerning selective auditory attention in humans through invasive electrophysiological monitoring of patient-volunteers undergoing epilepsy surgery. Previous work using non-invasive recording methods has generated conflicting theories regarding the neural generators of auditory attention waveforms (ie, processing negativity vs. N1 enhancement). The resolution of these competing theories impacts not only our understanding of selective auditory attention, but also psychological theories of attention (ie, early vs. late selection), and may give insight into the general organization of attention in humans, laying foundations for future treatment strategies. The Specific Aims are to: 1) Measure the latency, amplitude and topography of event related potential (ERP) components recorded directly from auditory cortex that are affected by attention. 2) Measure the firing rate of multi-unit activity in relation to selective auditory attention. 3) Measure the effect of attention on synchronous oscillations of local field potentials and firing patterns of multi-units.